2014 Volume 55 Issue 636 Pages 34-38
A nonlinear friction coefficient model was applied to finite element (FE) forming analysis in order to predict the formability in stamping steel sheets by press motion control with a servo press. This nonlinear friction coefficient model considers the effects of contact pressure, sliding velocity and sliding length on the coefficient of friction between steel sheets and dies in stamping. The results of cup drawing experiments showed that the formability in stamping by press motion control was predicted accurately by the developed method of FE forming analysis. A suitable press stroke position for applying press motion control to cup drawing was calculated to improve the wall thickness reduction at the punch shoulder portion effectively. By applying the developed method to the prediction of the effective press motion, motion control with a servo press can be efficiently applied in mass production systems such as automotive stamping lines.
